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  1. Rleo6965

    Noise Control Question

    You might try to connect both Voltage regulator IN to +12V. You connected the 2 voltage regulator in series.
  2. Rleo6965

    Capacitors...Again

    Why don't you have capacitor connected to pin2 of 555 to gnd? Tis is suppose to be astable oscillator. Right?
  3. Rleo6965

    DIY PCB

    Yes, you can print in Epson Desk jet then copy with Xerox toner :D
  4. Rleo6965

    problem with tip122 at high volt

    You need to replaced TIP122 with higher current and place heatsink for that transistor.
  5. Rleo6965

    Hello Im new this is my first post, I have lots a questions.

    Its much safer if you use isolation transformer . Specially if your using a Vacuum tube amp.
  6. Rleo6965

    Pull Up Resistor

    I don't think you need a pull up resistor in RB0. It was set as output and also you already have pull down resistor connected to the LED to Gnd. You need only to place pull up resistor in Input pin of PIC. But its also depend of your program to expext in its input i.e. High or Low input.
  7. Rleo6965

    Please help on inverters

    To answer question of daGenie. Basing in your diagram. There's no connection on pin 7 or discharge pin of 555 ic. It uses pin 3 output as discharge pin. So pin 3 was both serve as output and discharge pin for the 555. With this configuration of 555 it will not have a 50% duty cycle. To have a...
  8. Rleo6965

    Stereo receiver speaker takes a long time to come on and electronics safety

    Check first dc voltage of the big filter capacitor in the power supply if dangerous voltage still exist. Discharge it using the ac plug of your soldering iron. If you don't have bleeder resistor. . Then visually look for capacitors that have overheat or bulged top. That would be the culprit...
  9. Rleo6965

    Need help with regulator IC and how to make the control pin low when input is high

    Here's a very rough schematic without any protection. Do we need to place pull up resistor on pin 4 then connect other end of resistor to +14V?:)
  10. Rleo6965

    Please help on inverters

    Steve I miss that part.:D
  11. Rleo6965

    Please help on inverters

    It looks like a astable freq was 120 hz and divide by 2 by 4047 flip flop and RC on base of Q1 and Q2 was a sine wave forming circuit. So that secondary output of transformer would be 220V , 60 hz, simulated sinewave. 3V ac circuit w/ bridge rectifier and CA3130 will be the over voltage feedback...
  12. Rleo6965

    Please help on inverters

    Provide diagram. So we can help.
  13. Rleo6965

    Help identifying Component

    Do you have capacitance tester to test 100ufd/35V? I've just repair a Forward Converter Power Supply today. It's using Fairchild FPS ic 1M0880. Found 47ufd/25 of its VCC filter capacitor have changed value to 32ufd using my Fluke 79III Multitester. Just replaced with same value. Then PS for...
  14. Rleo6965

    Electronic Simulation Software

    Try this one. http://www.new-wave-concepts.com/ed/circuit.html
  15. Rleo6965

    Help identifying Component

    Just in case you already have replaced all damaged components and charger still have no or low output. Try to replace filter capacitor of pwm ic ( around 47ufd 25V ) connected to +VCC or pin 7 of pwm ic.
  16. Rleo6965

    PIC development board

    Don't forget to place current limit resistor to each LED. Unless Controller have built in current limit.
  17. Rleo6965

    100MHz clock Oscillator CFPS-73 test circuit

    Double check etch of pcb if connection was on correct pins of Clock Oscillator and broken connection.
  18. Rleo6965

    NE 555 timer

    I think you need you need 10 super bright LED for outdoor Stroboscope. You need a transistor to handle total current of 10 LED's. Of course place 1 current limit resistor in series. Try this link. You can adjust length of LED turn on time which makes LED brighter. http://danyk.wz.cz/ledstr_en.html
  19. Rleo6965

    Help identifying Component

    Its possible that you apply voltage 220V ac to 110V ac input pwm. That's component was MOV rated 120V. You can confirm if this was MOV by tracing etch of 2 ac line input that connects to MOV 2 terminals.
  20. Rleo6965

    DIY PCB

    Put small amount in clean white cloth and wipe over copper side of finished pcb. 1 or 2 coating will do. Let it dry for few minutes and you can now solder components. Varnish coating protect copper etch from contaminants such perspiration from your fingers. Without coating in your pcb will...
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